acerbate vs frosty

acerbate

adj
  • Embittered; having a sour disposition or nature. 

verb
  • To exasperate; to irritate. 

  • To make bitter or sour. 

frosty

adj
  • Having an aloof or inhospitable manner. 

  • Cold, chilly. 

  • Having frost on it. 

How often have the words acerbate and frosty occurred in a corpus of books? (source: Google Ngram Viewer )